#seqTest.py
class1 = ['zhangsan','lisi','wangwu','zhaoliu']
print('there are {} student in this class:'.format(class1.__len__()))
traverse(class1)

class1.reverse()
traverse(class1)

class1.sort(reverse = True)
traverse(class1)

class1.sort(reverse = False)
traverse(class1)
